Monthly outlook for Heisson, WA: average high 84.1°, average low 54.8°. That is 2.7° above the climate normal for August. Precipitation is expected on 0 days (about 0.0 inches), against a normal of 2 days and 0.7 inches. The warmest day looks like 23 August (93.7°), the coolest 11 August (48.5°).
84.1°/54.8°
Average high / low
+2.7°
Above normal
0 / 2
Wet days / normal
0.0 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
9 August – 18 August
81°
80.3°
+0.4°
19 August – 28 August
89.3°
77.8°
+6.4°
29 August – 7 September
at normal
75.9°
—
August records over 66 years
107.6°14 August 2023All-time high
42.8°28 August 2024All-time low
Climate normals and records are computed from the nearest reference point — Hockinson (7 mi).
Mon, 1081° / 51°0
81 °
Heisson, Monday, 10 August
Clear. High 81°, low 51°.
Pressure30.06 inHg
Wind5.2 mph W
Humidity39%
Visibility6.2 mi
Dew point48°
Tue, 1184° / 48°0
84 °
Heisson, Tuesday, 11 August
Clear. High 84°, low 48°.
Pressure30.06 inHg
Wind4.4 mph W
Humidity39%
Visibility6.2 mi
Dew point49°
Wed, 1274° / 54°0
74 °
Heisson, Wednesday, 12 August
Overcast. High 74°, low 54°.
Pressure30.03 inHg
Wind2.4 mph NW
Humidity80%
Visibility6.2 mi
Dew point58°
Thu, 1387° / 52°0
87 °
Heisson, Thursday, 13 August
Clear. High 87°, low 52°.
Pressure29.85 inHg
Wind4 mph W
Humidity42%
Visibility6.2 mi
Dew point54°
Fri, 1487° / 54°0
87 °
Heisson, Friday, 14 August
Clear. High 87°, low 54°.
Pressure29.85 inHg
Wind9.2 mph NW
Humidity33%
Visibility—
Dew point50°
Sat, 1581° / 52°0
81 °
Heisson, Saturday, 15 August
Overcast. High 81°, low 52°.
Pressure30.00 inHg
Wind7.4 mph NW
Humidity37%
Visibility—
Dew point48°
Sun, 1677° / 49°0
77 °
Heisson, Sunday, 16 August
Overcast. High 77°, low 49°.
Pressure30.06 inHg
Wind9.6 mph NW
Humidity40%
Visibility—
Dew point49°
Mon, 1780° / 52°0
80 °
Heisson, Monday, 17 August
Overcast. High 80°, low 52°.
Pressure29.97 inHg
Wind4.9 mph W
Humidity33%
Visibility—
Dew point46°
Tue, 1876° / 60°0.02
76 °
Heisson, Tuesday, 18 August
Light rain. High 76°, low 60°.
Pressure30.03 inHg
Wind3.5 mph N
Humidity68%
Visibility—
Dew point55°
Wed, 1984° / 61°0
84 °
Heisson, Wednesday, 19 August
Partly cloudy. High 84°, low 61°.
Pressure29.97 inHg
Wind6.4 mph SW
Humidity43%
Visibility—
Dew point55°
Thu, 2087° / 58°0
87 °
Heisson, Thursday, 20 August
Overcast. High 87°, low 58°.
Pressure30.03 inHg
Wind8.2 mph NW
Humidity33%
Visibility—
Dew point51°
Fri, 2188° / 60°0
88 °
Heisson, Friday, 21 August
Mostly clear. High 88°, low 60°.
Pressure30.06 inHg
Wind9.3 mph NW
Humidity34%
Visibility—
Dew point54°
Sat, 2291° / 56°0
91 °
Heisson, Saturday, 22 August
Overcast. High 91°, low 56°.
Pressure30.03 inHg
Wind8.9 mph NW
Humidity28%
Visibility—
Dew point48°
Sun, 2394° / 57°0
94 °
Heisson, Sunday, 23 August
Clear. High 94°, low 57°.
Pressure29.94 inHg
Wind9.8 mph NW
Humidity22%
Visibility—
Dew point45°
Mon, 2492° / 57°0
92 °
Heisson, Monday, 24 August
Clear. High 92°, low 57°.
Pressure29.91 inHg
Wind9.5 mph NW
Humidity26%
Visibility—
Dew point48°
From day 17 onward the outlook is built from 60-year climate statistics
Tue, 2578° / 55°0.07
78 °
Heisson, Tuesday, 25 August
Climate normal for this date — 60-year average.
Average high78°
Average low55°
Average precipitation0.07 in
Chance of precipitation15%
Record high93° (1996)
Record low47° (1975)
Wed, 2679° / 56°0.03
79 °
Heisson, Wednesday, 26 August
Climate normal for this date — 60-year average.
Average high79°
Average low56°
Average precipitation0.03 in
Chance of precipitation8%
Record high98° (1986)
Record low48° (1978)
Thu, 2778° / 57°0.06
78 °
Heisson, Thursday, 27 August
Climate normal for this date — 60-year average.
Average high78°
Average low57°
Average precipitation0.06 in
Chance of precipitation20%
Record high96° (2017)
Record low49° (1969)
Fri, 2879° / 55°0.04
79 °
Heisson, Friday, 28 August
Climate normal for this date — 60-year average.
Average high79°
Average low55°
Average precipitation0.04 in
Chance of precipitation10%
Record high99° (2017)
Record low43° (2024)
Sat, 2977° / 56°0.09
77 °
Heisson, Saturday, 29 August
Climate normal for this date — 60-year average.
Average high77°
Average low56°
Average precipitation0.09 in
Chance of precipitation22%
Record high95° (2022)
Record low47° (1965)
Sun, 3075° / 56°0.08
75 °
Heisson, Sunday, 30 August
Climate normal for this date — 60-year average.
Average high75°
Average low56°
Average precipitation0.08 in
Chance of precipitation32%
Record high100° (2022)
Record low47° (1964)
Mon, 3176° / 55°0.07
76 °
Heisson, Monday, 31 August
Climate normal for this date — 60-year average.
Average high76°
Average low55°
Average precipitation0.07 in
Chance of precipitation25%
Record high99° (1987)
Record low47° (2006)
Tue, 0176° / 55°0.09
76 °
Heisson, Tuesday, 1 September
Climate normal for this date — 60-year average.
Average high76°
Average low55°
Average precipitation0.09 in
Chance of precipitation23%
Record high94° (1988)
Record low43° (2021)
Wed, 0277° / 55°0.07
77 °
Heisson, Wednesday, 2 September
Climate normal for this date — 60-year average.
Average high77°
Average low55°
Average precipitation0.07 in
Chance of precipitation20%
Record high100° (1988)
Record low45° (1960)
Thu, 0376° / 55°0.07
76 °
Heisson, Thursday, 3 September
Climate normal for this date — 60-year average.
Average high76°
Average low55°
Average precipitation0.07 in
Chance of precipitation20%
Record high98° (1988)
Record low43° (1964)
Fri, 0476° / 55°0.04
76 °
Heisson, Friday, 4 September
Climate normal for this date — 60-year average.
Average high76°
Average low55°
Average precipitation0.04 in
Chance of precipitation20%
Record high104° (2017)
Record low46° (2000)
Sat, 0576° / 55°0.06
76 °
Heisson, Saturday, 5 September
Climate normal for this date — 60-year average.
Average high76°
Average low55°
Average precipitation0.06 in
Chance of precipitation20%
Record high98° (2024)
Record low47° (1969)
Sun, 0675° / 54°0.11
75 °
Heisson, Sunday, 6 September
Climate normal for this date — 60-year average.
Average high75°
Average low54°
Average precipitation0.11 in
Chance of precipitation20%
Record high92° (2024)
Record low46° (1969)
Mon, 0775° / 55°0.06
75 °
Heisson, Monday, 7 September
Climate normal for this date — 60-year average.
Average high75°
Average low55°
Average precipitation0.06 in
Chance of precipitation18%
Record high95° (2011)
Record low44° (1960)
About the monthly outlook
How accurate is a 30-day forecast?
The first 16 days come from weather models — reliable for the first 3–5 days and progressively less so after that. Days 17 through 30 for Heisson, WA are built from the climate normal, the 60-year average, so they show typical weather for those dates rather than a specific forecast.
What does "above normal" mean?
We compare the forecast against the climate normal for those exact calendar days, computed from 60 years of observations. The deviation shows how much the coming month differs from a typical one.
Where do the 66-year records come from?
They are real temperature extremes recorded in Heisson, WA since 1960: the highest and lowest reading for each calendar date, with the year it happened.
How often is it updated?
The forecast portion refreshes every hour; the climate portion is based on long-term data and stays stable.